Cap for armor-piercing projectiles.



A. G. JACK. v v 7 CAP FOR ARMOR PIERGING PROJEGTILES. PPPP IUATION FILED 11.13, 1910.

987,073; Patented 111111.14, 1911.

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I v r/ GAP FOR 'ARMOB. PIERGING EEEEEEEEEEE PPPPPPPPPPPPPPPPPPPPPPPPPP 0.

987,073. Patented Mar. 14, 1911.

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v A. G. M. JACK. GAP FOR ARMOR BIERCING PROJBCTILES. APPLICATION FILED APR.13, 1910. 987 073, Patented Mar. 14, 1911.

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'so-shaped on its toits hollow point or forward extension that I when the cap is fitted to a projectile andthe -projectile fired at an armor plate, pressure transmitted to the solid front end portion of tension strikin solid front en portion-t press in an 111-- 111'3! rearward direct-ion. U

UNITED STATES PATENT men.

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To all gelatin itmay c mera.- 7 I Be 1t known that I, ALEXANDER GEORGE Cap for .'Armor- Piercing l?rojeetiles, of whieh the following isa specification. I This iIWGIltlOll has reference to metal caps" .kind whereby the point of the projectile to which it is applied can be supported against rupture in a better manner than heretofore usual. For this urpose the cap proper is orward end and-s0 united the cap proper upon itshollow forward exthe plate will cause such ward instead :of an outward direction upon and around the pointed end'xportion of the projeqtileand thereby support such portion of the projectile inamore effective manner than heretofore usual, against fracture, upon contact'with the plate. To enableia hollow pointed cap toact'in this'manner, the front end portion of-t he cap proper is made of "concave .or inverted conical or'equivalent cup shape and the baseor rear end portion of thehollow point which is integral with .the cap, is made of gradually. increasing thickness rearward and on its inside with a curved surface of largeradius merging into the surface of the cupped recess in the front end of the capso as toform a connecting portion between the ca and hollow point of ickness and strength on a projectile fitted with such a hollow pointed cap strikiing an armor plate and-the hollow point of the cap flattening, pressure upon the thick- 'ened edge portionof the concave or cupped gradually increasing t front end ofzthe cap proper will cause the tap not only to 'su' port the point of the shell but further it will also cause the cap to exert an inward or constrictive pressure at and around the point of the'projectile and thus prevent orassist in preventing rupture of Specification of Letters Patent.

Application filed April 11e, 1,91o.' 'Serial-No .f555,1 33.

subjectof the King of. Great Britain-and Ire1and,residi t Erin- 'clifie', Shefiield, iuthe countyof York, England, have invented Improvements in an armor piercing proe and .havingintegral, therewith a holand thin and therefore sing. In the example'now solid 60.

srmrrrnnp, ENGLAND,

such point and consequent rupture' of the entire shell when may e of any desired dimensions and o .any' suitable or desired shape'exterradius orradii,'.or conical, with an extreme I the same reaches'the plate. The hollow point or forward extension of the ca Patented n. i4; 19111,

I1al1y,'as for example ogival, of anydesire'd front end ofpointed, rounded or other shape as may berequired and as well understood. Internally, the hollow pointrfnaybe of a shape that conforms more or less to that of its exterior andof such size that thewall constituting the hollow but the base plortionthereof, wiere it joins the body of the'cap, is as hereinbefore menpo1nt, or extension, s comparat vely'thln for the, reater part tioned,-Inad of gradually increasing thickness in a rearward v large mternal radlusor-curvatnre so as to strengthen the connectlon between the point this. part when the capped project-ilestrikes an armor plate.

"In the accompanying illustrative drawings, F1gure 1 shows the ogival-pointedfront end portion of an armor piercing projectile fitted with ahollowpointed cap constructed. according to the present invention, the pro inside elevation and the cap in central'longitudinal section. Figs. 2,

jectilebeing shown direction, and with a cap and minimize risk of fracture at i 3'and 4 are-similar viewsto Fig. 1 showing 7 modified forms of caps.

I In Fig. 1,. the metal cap a is formed with a comparatively. short hollow pointed portion I) that is-integral with the cap proper, I

the hollow pointed cap is obtuse angled conical front general external formation and -relative dimensions of the, hollow pointed cap being, for a particular caliber of the proyectile, substant ally those of the describedin the specification of British The solid front end portion of the cape is here'shown as made, for the purpose hereinbefore described, with a recess h of inverted conical or concave shape and the surfuceof the portions 0 uniting thecap proper with 'ItS hollow point being made comparatively port-ionic connected bya curved or a surface f with the conical rear end.

tters Patent No. 19104 of 1907.

.usual to closely fit the projectile z' with which the cap is to be used.

Fig. 2 shows a cap with a hollow point- 6 and coned, cupped or concave shaped recess .i h as in 1, but the oint Z) is made longer and of ogival shape w of the cap proper a is made with a large radius of curvature, say equal to about five times the'caliber of the projectile, or more,

to facilitate flight of the capped projectile, as now well understood.

- Fig. 3 shows'a similar construction of cap to that shown in Fig. 2 except that the exte-. rior of the cap with its hollow point is made with a singlelarge radius of curvature, for

the purpose mentloned.

Fig. 4 shows a modification in which the exterior of the cap a and its hollow point I) is of conical shape throughout except at the extreme point which is of rounded shape.

When a projectile provided with a cap constructed as described strikes a hard faced armor plate, the hollow forward portion of the cap will exert great pressure through the thickened edge portion 0 of the cap upon the cap proper and tend to force the metal of the cap inward upon the pointed end portion of the projectile so as to support the same against fracture. The hollow forward portion of the cap will not however be at once dispersed or separated from the cap proper but will on the contrary be caused to assume a flattened or collapsed shape as approximately indicated in dotted lines in Fig. 2,50 as to form a surrounding strengthening ring'b which will delay the breaking up of the cap a and will moreover further reinforce the supportlng and constrictive action of the cap around the pointed portion of the projectile z' in a manner which is not possible when the cap is provided at its front end with a flat convex or forwardly projectin conical surface, and when the hollow pointe or forward extension of the cap is made separate from the cap proper and mechanically attached thereto. The above men tioned action of .the improved cap has been confirmed in a striking manner in several instances. Thus, in recent tests carried out with six inch armor piercing projectiles fitted with hollow pointed caps constructed ac cording to this invention and with solid caps, -both kinds of'caps being externally of exactly. the same shape and dimensions, it was found that the projectile fitted with the solid cap when 'firecl at at low velocity, namely below L900 feet per second, against a Krupp cementedlplate of a thickness equal to the diameterof the projectile did not succeed in perforating the plate and was broken '.up on the surface of the late whereas a projectile fitted with the iiollow pointed cap merges intothat of the He the external shape 7 other shape, open at its extension the rear end 'when fired not only succeeded in completely perforating the plate at a still lower velocity but was afterward recovered in an unbroken condition. I

A hollow pointed cap such as described can be constructed by forming the cap proper a with a hollow forward extension, such as is indicated in dotted lines at Z) in Figs. 1 and 2, of more or less cylindrical or front end and closed at its rear end by the front end portion of the cap proper which is preferably made of the concave or inverted hollow conical shape hercinbefore referred to, the hollow forward extension 72 which may be of approximately equal or tapering thickness, being afterward closed in under pressure, able die or dies, as for example a cupped die h, also shown in dotted lines in Fig. 1, to form a. hollow closed point or extension of the desired shape. The hollow forward extension 1) of the metal cap a may, if desired, be heated to facilitate its being closed in, or it may be closed in while in the cold state.

\Vhat I claim is i 1. A cap adapted to fit closely over and around the pointed nose of an armor pierc ing projectile and having a recessed front end surface and a hollow pointthat extends forward from the marginal edge portion of the said recessed front endof the cap and is integral therewith.

2. A cap adapted to fit over and around the pointed nose of an armor piercing pro jectile and having a recessed front end surface covered by a hollow point or forward portion of which is united integrally with the marginal edge portion of the recessed front end of the cap by a. connect'ng portion of gradually in creasingthickness and strength in a rear ward direction.

, 3. A cap provided with a solid rear portion adapted to 'fit over and around the pointed nose of an armor piercing projectile, saidsolid rear portion having a recess in its front surface, and a hollow point extending forwardly from and integral with said solid rear portion, the inner surfaces of the recess and fthe hollow in the point being merged one into the other by a curved surface having a comparatively large radius.

4. A cap having a solid rear portion adapted to fit over and around and support the pointed nose of an armor piercing projectile and having a recess in the front surface of said rear portion and a hollow point covering thesaid recessand integral witl". the cap and of ogiva-l shape externally, saic hollow point being made thin for the greatei part of its length but of gradually increas ing thickness at the part where it joins tin recessed front end portion of the capsub stantially as described and shown.

5'. For an armor piercing projectile hav as by a suit- 1 ing a pointed no se, a cap ada ted to fit around andusupnort the pointed nose of the projectile and having a hollow point or forwardextension integral with the cap proper and a front end surface of cupped shape T surface of the connected e 6. A metal cap recessed on its rear side to covered by said hollow point and the surface of which gradually merges into the inner surface of the. hollow point, the inner curved parts having a 00111- paratively larger radius.

' fit over and around the pointed nose of an armor piercing projectile and having at its Lj solid front-end portion a recess of inverted conical shape and a hollow point integral,

with thecap-and covering the recessed front end thereof, the surfaces of the recessed front end portion of the cap and :of the inscribed for the'purpose set forth.

terior of the hollow point gradually merging one' into theother, substantially as de- 7. A cap for an armor piercing projectile having a solid front end portion recessed on itsrear side to fit over, around and sup port the pointed nose of a projectile andformed on its front side with a recess of conical shape and with a hollow point that extends beyond and covers the recessed front endportion 'ofthe cap and isintegral with the marginal edge portion thereof, the metal .at the junction of the two parts being of gradually lIlCI'BZISul thickness in a rearward direction.

8. A one piece, integral cap having a solid rear portion adapted to fitsnngly over and around the pointed .noseof an armor piercing projectile and having a hollow, forwardly extending point. 91 A one-piece integral cap having a solid rear portion and awall of gradually dimin-- 10. A. one piece integral cap ha'ving a solid rear portion adaptedto fit snugly over and around the pointed nose ofa projectile, and a hollow point "forwardly extending from the solid rear portion, a wall forming said *hollow point. and connect-ingthe same to the rear porti'onbeing thickened where it joins the rear portion..-

Signed at Hecla Works, Shelfieldjz'i ork shire, England this 22nd. day of March 1910.

ALEXANDER GEORGE MACKENZIE JACK. Vitnesses: i

(in-H. HEMsoLL, EL Ronenns.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. 0. 

